The HOL Light rewriter (REWRITE_TAC etc.) and simplifier (SIMP_TAC etc.)
have default sets of (conditional) equations and other conversions that are
applied by default, except in the PURE_ variants. The latter are normally
term transformations that cannot be expressed as single (conditional or
unconditional) rewrite rules. A call to set_basic_convs l where l is a list
of items ("name",(`pat`,conv)) will make the default conversions just that set,
using the name name to refer to each one and restricting it to subterms
encountered that match pat.

FAILURE CONDITIONS

Never fails.

COMMENTS

Normally, users will only want to extend the existing set of conversions using
extend_basic_convs.